#! /bin/bash

##注意：
	#!=,==用于子串比较
	#-ne,-eq,-gt,-lt用于整型比较
echo "Please write a passwd!"
count=3
read psd

while [ "$psd" != "centos" -a $count -gt 0 ]; do
	count=$[count-1]
	printf "Enter again!\n"
	read psd
	if [ $count -eq 1 ];then
		break 1
	fi
done





























